a) (4x+5)/14+(2x-6)/6=4(3x-11)/21+9/14
(4x+5-9)/14-4(3x-11)/21+(2x-6)/6=0 aducem la acelasi numitor
[3(4x-4)-8(3x-11)+7(2x-6)]/42=0
(12x-12-24x+88-14x-42)/42=0 ·42
-26x+34=0
2(-13x+17)=0
-13x+17=0
-13x=-17 ·(-1)
x=17/13
b)(7x+6)/30-(2x-9)/12=(2x+13)/30-(x+8)/20+2/3
[2(7x+6)-5(2x-9)-2(2x+13)+3(x+8)-2·10)]/60=0 ·60
14x+12-10x+45-4x-26+3x+24-20=0
3x+35=0
3x=-35
x=-35/3
x=-11,(6)
c)(3x+7)/10- (4x- 9 )/18=(12x+7)/45+ 1/10
[9(3x+7)-5(4x-9)-2(12x+7)-1·9]/90=0 ·90 si simplificam
27x+63-20x+45-24x-14x-9=0
-31x+99=0
-31x=-99 ·(-1)
x=99/31
nu stiu daca e scris bine ex.pt ca nu stiu exact ce este la numarator si la numitor